The activated complex is currently envisioned as an energy-rich molecule located on the reaction path between two interconvertible reactants, and the reaction rate is supposed to be proportional to the concentration of this molecule. Eyring explained that this complex corresponds to a saddle point in a potential energy landscape and is like any other molecule, except in the degree of freedom in the negative curvature it is flying. The relatively flat curvatures in the vicinity of the saddle point would allow to identify it with a stable chemical compound [1]}. But this intuitive conception obviously ignores the notion of elementary reaction. Let us consider the reversible first order transitions
